Baleen Filters 102 sq. ft. Pool Filter Replaces Unicel UHD-SR100, Pleatco PSR100-4, Filbur FC-2550-Pool and Spa Filter Cartridges Model: AK-8020 Media Area 102 sq ft, 8 11/16" OD, Open Hole: 4 3/16" Top, Open Hole: 4 3/16" Bottom, 25 11/16" Long, AK-8020 Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 102 sq. ft. Universal Pool Cartridge for 8 11/16" OD Pentair - PacFab, Sta-Rite Filter, replacement of Unicel UHD-SR100, Pleatco PSR100-4 Baleen Filters Top: Open Hole: 4 3/16" Bottom: Open Hole: 4 3/16" Perfect Fit - Extremely Durable - Wash and Reuse - Most Energy Efficient - Withstands High Pressures and Temperatures